1. Field of the Invention
The present invention relates generally to a digital VTR (Video Tape Recorder) for intermittently recording an input image. The present invention further relates to a video recording/reproducing apparatus such as a digital VTR.
2. Description of the Prior Art
A digital VTR for storing in a memory actual data (input video/audio data or its compressed data) and recording, every time data for each block are stored, the data for the block on a magnetic tape at the time of recording, while intermittently reading out the data recorded on the magnetic tape for the block, storing in the memory the data read out of the magnetic tape, reading out the data stored in the memory, and reproducing and outputting the read data at the time of reproduction has been known.
In such a digital VTR, it is difficult to feed the magnetic tape at a speed higher than a normal reproduction speed to perform reproduction, that is, perform fast-forward play (including fast-backward play). In order to perform fast-forward play, it is necessary to previously produce data for fast-forward play on the recorded data and to use as a formatter special one having such a function.
An object of the present invention is to provide a digital VTR capable of performing fast-forward play without using as a formatter special one.
In the above-mentioned conventional digital VTR, when a new block is recorded on a block which has already been recorded from its halfway part when recording is started, the block which has already been recorded and the new block are recognized as one block at the time of reproduction. Consequently, the capacity of the one block is larger than that of one recording block previously determined.
When such a phenomenon occurs at the time of recording, data corresponding to one block which have been read out of the magnetic tape cannot be recorded on the memory at the time of reproduction, so that normal play cannot be performed. Even in such a case, a memory having a large capacity must be prepared in order to perform normal play.
An object of the present invention is to provide a digital VTR capable of preventing a new recoding block from being recorded on a recording block which has already been recorded from its halfway part when recording is started.
An image recording/reproducing apparatus for compressing an image picked up by a monitoring camera by an image compressor meeting a JPEG (Joint Photographic Expert Group) standard (hereinafter referred to as a JPEG image compressor), for example, and then recording the compressed image on a video tape, reading data recorded on the video tape, then expanding the read data by an image expander, and outputting the expanded data has already been developed.
At the time of recording, every time data representing the image compressed by the image compressor is stored in the memory, and data corresponding to one block having a predetermined capacity are stored in the memory, the data corresponding to the one block are successively read out and are recorded on the video tape. At the time of reproduction, every time the data read out of the video tape are stored in the memory, and data corresponding to one block having a predetermined capacity are stored in the memory, the data corresponding to the one block are successively read out and are fed to the image expander.
In the video recording/reproducing apparatus, a head address storing field (frame) data corresponding to each field (each frame) out of data corresponding to one block which are stored in the memory is difficult to recognize. Accordingly, it is difficult to perform special play such as reverse play, fast-forward play, or fast-backward play.
An object of the present invention is to provide a video recording/reproducing apparatus capable of performing special play such as reverse play, fast-forward play, or fast-backward play.
In the above-mentioned conventional video recording/reproducing apparatus, when a search is performed on the basis of data added to video data, field (frame) data including the added data are read out. Accordingly, it takes long to perform the search.
An object of the present invention is to provide a video recording/reproducing apparatus capable of quickly performing a search.